The invention relates to a drive apparatus for a mail-processing system which has an enclosure-collating path, which is intermittently driven at least in one end section and has conveying fingers arranged on endless, circulating conveying chains or conveying belts, and an inserting station, which follows the end of the enclosure-collating path, in the conveying direction of the latter, and by means of which sets of enclosures formed on the enclosure-collating path are inserted into envelopes, which are conveyed up on an envelope-filling table, parallel to the enclosure-collating path, by means of an envelope-gripper chain and are held open opposite the inserting station and, once filled with the sets of enclosures, are conveyed away from the inserting station by means of the envelope-gripper chain.
A drive apparatus of this type is disclosed by German patent 198 30 337. It contains a drive shaft which is driven by a stepping mechanism, revolves intermittently and extends transversely with respect to the conveying direction of the enclosure-collating path and on which chain wheels or rollers are fixed, over which the conveying chains or conveying belts of the intermittently driven section of the enclosure-collating path are positioned. This intermittently revolving drive shaft leads to a first bevel gear mechanism which is arranged in the region of the envelope-filling table and which, via a shaft extending along the envelope-filling table, is coupled to a further bevel gear mechanism, which ultimately serves for driving a chain wheel over which the envelope-gripper chain is positioned.
In the known apparatus, difficulties are presented in adjusting the positions of the gripper claws of the gripper chain, for example for adjusting to different envelope formats, before the inserting station or before an envelope turning station connected downstream in the direction of conveyance of the enclosure-collating path. The drive path from the stepping mechanism as far as the driven chain wheel of the envelope-gripper chain in the known drive apparatus has two bevel gear mechanisms, is massive and correspondingly sluggish, so that, on account of the acceleration and the retardation in the course of the intermittent activation, comparatively high torques occur, which cause increased wear. Finally, a modular design of the entire mail-processing system is made more difficult in the case of the known drive apparatus.
German patent 129 43 759 discloses an apparatus for feeding envelopes to an envelope-filling station, in which the envelope-filling table having an intermittently driven, circulating envelope-gripper chain can be displaced as a whole with respect to a substructure. The substructure contains a drive motor with an orientation of the drive shaft parallel to the conveying direction of the envelope-gripper chain and, coupled thereto via a reduction belt mechanism, an adjustable-length tapered shaft arrangement, which permits the envelope-filling table to be displaced relative to the substructure, the tapered shaft arrangement being coupled to a bevel gear mechanism in order ultimately to be able a drive a drive chain wheel of the envelope-gripper chain with an axis of rotation oriented transversely with respect to the conveying direction of the envelope-gripper chain.
Here, too, the result is a structure of the drive which is comparatively complicated and afflicted by sluggish masses and also the necessity to provide a drive motor separate from the usual drive means of the mail-processing system.
The invention is intended to achieve the object of configuring a drive apparatus for a mail-processing system in such a way that a simplification of the structure and a reduction in its susceptibility to wear is achieved by reducing the inertial masses. In particular, the structure of the drive apparatus is intended to simplify the adjustment of the position of the envelope-gripper chain along the enclosure-collating path.